Donald Trump allegedly faked a glowing note from his doctor during the 2016 presidential campaign, then spent the next several months launching attacks against Hillary Clinton for her “secrecy” about her health issues.

This week, former Trump doctor Harold Bornstein admitted that a now-infamous 2015 letter describing Trump’s health in unusually glowing terms was actually dictated by Trump himself. Bornstein told CNN that Trump told him what to put in the letter, which claimed that Trump’s “strength and physical stamina are extraordinary.”

There were many questions about the letter at the time, especially as Trump was reportedly overweight and had a famous penchant for eating fast food and getting little sleep. But Donald Trump pushed aside the questions and instead took a focus on opponent Hillary Clinton’s health, helping to push some fringe and potentially baseless conspiracies about her health.

While he was on the campaign trail, Trump frequently questioned whether Clinton had the proper health and stamina needed to serve as president. He was accused of fueling right-wing conspiracies that Clinton was secretly in failing health, with reports from the fringes of the internet claiming she was suffering from everything from epilepsy to a degenerative brain disorder acquired by eating human flesh.

Trump supporters, including Fox News host Sean Hannity, also seized on a video in which Clinton had an exaggerated reaction to a group of reporters asking her questions to insinuate that Clinton was having a seizure. Trump was also accused of fueling these conspiracy theories at his rallies.

“Importantly, she also lacks the mental and physical stamina to take on ISIS and all of the many adversaries we face — not only in terrorism, but in trade and every other challenge we must confront to turn our great country around,” Trump said at a rally in the summer of 2016 (via the BBC).

Trump’s frequent references to Clinton’s health even prompted a sharp reply from Clinton’s campaign, NPR noted. A campaign spokesperson accused Trump of “peddling deranged conspiracy theories in a desperate attempt to change the subject.” But the issue reached the forefront after Clinton fell ill with pneumonia during Labor Day weekend and was forced to take several days off the campaign trail.

There had long been doubts about whether the letter from Donald Trump’s doctor was genuine. The 2016 NPR article that laid out Trump’s efforts to spread conspiracies about Hillary Clinton’s health noted that “the letter was written in Trumpian style” and stated that he was in glowing health despite evidence to the contrary.